Electric furnace.



J. W. MOPFAT.

- BLEOTRIQ FURNACE. APPLICATION IILED .NQV. 22 1913;

Patented Sept. 1, 1914.

YINVENT'OR WITNESS E15- ATEZW' JAMES W. MOFFAT, OF TORONTO, ONTARIO, CANADA.

nnnc'rnrc FURNACE.

Specification of Letters Patent.

Patented Sept. 1, 1914.

Application filed November 22, 1913. Serial No. 802,433.

of the city of Toronto, Province of Ontario,

Canada, have :rnvented certain new and useful Improvements in Electric Furnaces, of

which the following is a specification.

This invention relates to furnaces of the type shown in Canadian Patent No. 124,903, and United States Patent No. 950,595 and allsuch furnaces as are intended to be used in carrying out the reduction of ores by showering them through a reduction chamber into an electrically heated bath or crucible. The prior furnace referred to comrised a stack, a reduction chamber, and a bath or crucible, all arranged in fixed relationship to one another. While excellent results have been attained with the said furnace, I find that much difiiculty is experienced in getting entirely rid of the slag and consequently in eliminating from the metal as large a proportion of certain impurities as is necessary in the production of very high grade steel, and the present furnace does not lend itself readily to the production of alloy steel or steels which require the introduction of special ingredients into the bath. Trouble has also been experienced in pouring the molten metal from the furnace.

It is my object to so construct the furnace as to overcome the disadvantages referred to and to enable steel of any desired quality or character to be produced direct from the ore and in the one furnace.

I attain my object by dividing the furnacebetween the reduction chamber and the crucible so that the latter may be tilted substantially as and for the purposes hereinafter described and as illustrated in the accompanying drawings in which Figure '1 is a front elevation partlv in section of my improved furnace, and Fig. 2V-is a side elevation of the same.

In the drawings like numerals of refer ence indicate corresponding parts in the different figures.

'1 is the reduction chamber of the furnace supported in any ordinary manner from the floor 2. This reduction chamber has an opening therein communicating with the stack 3, which is preferably supported on the reduction chamber. The stack is provided with a suitable opening 4 through which the ores to be treated in the furnace may be showered.

I her.

5 are the openings for the introduction of air into the reduction chamber for purposes described in the prior patents hereinbefore referred to.

G is the bath or crucible in which the reduced ore ismelted and the metal separated from the slag. The bath or crucible is electrically heated, 7 being the electrodes which preferably project through the top of the crucible to any suitable position in the interior. This crucible has an opening 8 in its top which when the crucible is in normal position registers with the opening 9 in the bottom of the reduction chamber.

10 is the tap hole or spout through which the slag and molten metal are withdrawn.

The crucible is supported in any suitable manner so that it may be tilted to facilitat-e the withdrawal of slag through the tap hole and the subsequent pouring of the molten contents of the crucible.

In the drawings I show the crucible as provided with trunnions 11, which are journa led on hearing braces 12, which are vertically adjustable in the guides 13 by means or screws 14. The actual tilting of the crucible may be accomplishedin many different ways. I show for this purpose two hydraulic cylinders 15, which are pivotally connected with a suitable stationary part, and have their piston rods 16 pivoted on the crucible.

By suitablyoperating the hydraulic tilting apparatus the crucible maybe tilted as desired, but of course any other apparatus may be employed for this purpose.

In the embodiment of the invention shown in the drawings the crucible is shown as trunnioned in a plane intersecting the vertical axis of the furnace, consequently to enable the crucible to be readily tilted, it is necessary to lower it somcwh at. so'as to clear it from the lower end of the reduction chamber. After the crucible has been tilted back to its normal position it may be again raised by means of the screws 14 to cause it to fit closely the lower end of the reduction cham- If the trunnions were located closer to the back of the crucible the screws 14 might be dispensed with.

The advantages of the construction described are numerous. The crucible maybb tilted so as to bring the slag level in the line with the tap which 111 kes it an eyceedingly easy matter to dra ofi ever portion of the sla g, after which by rther tilting the crucible, the molten metal may be poured.

If it be necessary to subject the material to further treatment after reduction, as for example by the introduction of other materials, such materials may be readily inserted through the opening 8 which may then be closed by means of any suitable refractory cover or plug. The crucible may then be tilted back to its normal position for' further heating the plug preventing any escape of heat to the upper part of the furnace.

What I claim as my invention is:

1. A furnace comprising a stationary reduction chamber; and a tiltable crucible arranged below and normally in communication with said reduction chamber and adapted when tilted to substantially close off the said reduction chamber.

2. Afurnace comprising a stationary reduction chamber; a tiltable crucible arranged below and normally in communication with said reduction chamber and adapted when tilted to substantially close off the said reduction chamber; and means for lifting said crucible to bring it into close connection with the lower part of the chamber.

3. A furnace comprising a stack; a reduction chamber into which the stack opens said reduction chamber having an opening at its lower end; a tiltable crucible ar-' of the crucible may be varied by tilting the latter; and electrodes extending into the in terior of the crucible from the outside.

A furnace comprising a stationary reduction chamber; a tiltable crucible ar- 'anged below and normally in communication with said reduction chamber and adapted when tilted to substantially close off the said reduction chamber; and electrodes extending into the interior of the crucible from the outside.

Toronto, Ont. this nineteenth day of November A. D. 1913.

JAMES W. MOFFAT.

Signed in the presence of- E. P. HALL, E. Law.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents,

I Washington, D. C. 

